This invention relates to the dehydrohalogenation of a 1- or 2-haloethyldibromobenzene. More particularly, this invention relates to the dehydrohalogenation of a haloethylhalobenzene in an aqueous alcoholic alkaline medium using a phase transfer catalyst. This invention also relates to the dehydrohalogenation of 1- and 2-haloethyl monobromobenzene, 1- and 2-haloethyl polybromobenzene, and mixtures thereof.